All you need is:
- Foam scraps (ours were off cuts from foam stickers so already had sticky backing, but if yours don't just use white glue)
- Bottle tops
All you do is cut out shapes from the foam to fit the size of the bottle tops, stick it on, and stamp away!
I also decided to buy a washable paint stamp pad from the craft shop for $4 to make this activity potentially less messy. However, once Bean gets the hang of it I'll just use poster paint on a plate for more color variation :-)